The present description relates to an automatic transmission for an automotive vehicle, and more particularly to a control apparatus for an automatic transmission.
In a case of an automatic transmission for an automotive vehicle, a valve body is arranged. A control valve mechanism which controls hydraulic pressures for engagement of frictional elements and other functions of the automatic transmission is installed in the valve body. It is common that a plurality of solenoid valves which actuates the control valve mechanism is attached to the valve body.
Also, it is common to provide an electronic controller which receives signals from various sensors and outputs control signals to the solenoid valves. It is known and, for example described in U.S. Pat. No. 6,530,856B1, that an electronic controller is also arranged in the transmission case. It is described in the '856 patent that a valve body is arranged in the bottom of the transmission case, a plurality of solenoid valves and an electronic controller are attached to the valve body as well as an oil temperature sensor, a speed sensor, etc. The prior art can simplify arrangement of a wiring harness which connects the electronic controller, the solenoid valves and the sensors.
However, in the prior art, the electronic controller may be located so close to the solenoid valves that electromagnetic waves generated by actuation of solenoid valves affect the function of a central processing unit and other electronic parts in the electronic controller.
Therefore, there is room to improve the arrangement of valve body, electronic controller and solenoid valves in the transmission case.